Born and brought up in Canada by his ethnic Indian parents, 34-year-old filmmaker Richie Mehta is an artist between two worlds. His work is a personal, heartfelt blend of his western environment and his Indian roots, as shown by his debut film Amal (2007), a modern-day fairytale centring on a New Delhi auto-rickshaw driver who leads an honest life amid widespread corruption.

Siddharth continues Mehta's exploration of Indian reality with a compelling story about what happens when the titular boy fails to return home to celebrate Diwali (the Hindu festival of lights) with his family.

Inspired by a real-life encounter he had on a New Delhi street, the drama addresses the fraught topic of child abduction by focusing on the desperate search by Mahendra (Rajesh Tailang), a poor street vendor, and his wife, Suman (Tannishtha Chatterjee), for their 12-year-old son, who had been sent by his father to work in a factory hundreds of kilometres away.

Mehta's filmmaking is closely bound up with his attempt to come to terms with his dual national identity. His first trip to India proved a key event for his personal life and, later on, for his work.

"I grew up in a household where we used to speak Hindi and my grandmother would cook Indian food every day," he says. "I had a very romantic notion of India,[but] when I finally went there at the age of 16 it was the worst experience of my life because I understood that, compared to Indian standards, I was one of the richest people around. This was such a painful realisation that I decided not to go back until I could address this issue for work."

A couple of years later, while studying filmmaking in Toronto, he found the opportunity to do so. His brother Shaun, on a university exchange in India, wrote a short story about an auto-rickshaw driver and asked him to read it.

"I was so moved by the story because it addressed those mixed feelings that I was having; this love I had for the culture and a 'where do I fit into it?' kind of sadness. It was Amal, my first short film and, later on, my first feature film as well."

The experience of shooting Amal changed Mehta's relationship to India. "I went to Delhi and met sublime actors like Naseeruddin Shah ( Monsoon Wedding), Roshan Seth ( Gandhi) and Seema Biswas ( Bandit Queen). I was very privileged to work with these great actors, to learn and understand their history and culture. From that moment on I was not just observing, I was living there, I was part of it," he says.

Following Amal's success, Mehta was hired by Walt Disney Pictures to direct its first-ever Hindi language film, and although the project was eventually dropped, a chance meeting provided him with the subject for his next film.

"On Delhi's streets I met a rickshaw driver, the person whose real story Siddharth is based on. He asked me if I knew where Dongri [in South Mumbai] was, a place where missing children possibly end up. 'I lost my son a year ago and I'm trying to find him,' he said to me. The guy didn't have a picture of his son, nor was he able to spell his name. I couldn't help him."

Even after returning to Canada and while shooting his sci-fi drama I'll Follow You Down (2013), Mehta remained haunted by this story. "I kept wondering if the boy's father, after one year, was still asking people for Dongri, he would never give up. His resilience was so strong."

Mehta decided to return to New Delhi to make another film. "In Amal I had merely investigated my views on India. Now I felt I had to explore a different way of thinking."

One of Mehta's major concerns was getting the characters' psychology right. This meant venturing into the less savoury areas of India, including places that were notorious for child trafficking. Still, rather than dwell on the uglier aspects of the country, he says his film is intended to show "how dignity and moral values can emerge amid a dark world".

Mehta says he was emotionally impacted by his film. "When I saw the rough edit of Siddharth for the first time, I started crying ... This was the biggest satisfaction I had."